Apparatus for distribution of logs into grinder supply shafts

Abstract

Apparatus is disclosed for the distribution of logs into the supply shafts of a plurality of successive grinders from a conveyor line consisting of several belt, chain or other conveyors placed in succession and carrying the logs transversely thereon. The logs are passed from one conveyor to the next and distributed into supply shafts through gaps between the conveyors, which are automatically started for moving the logs on the conveyor line so as to fill the supply shafts. The equipment previously known and used for this purpose has several disadvantages, e.g. the need for sorting of the logs, unnecessary operation of the conveyors, overfilling of the line, etc. The present invention obviates these drawbacks in that the line is provided with sensors for sensing the height of the stack of logs on the conveyor line above each grinder supply shaft, at least two sensors being located above the level of the conveyors so as to control the conveyors adjacent to the shaft, so that they will be started, in motion either simultaneously or separately towards the supply shaft therebetween to ensure that there is always a sufficient supply of logs at the grinder.

I claim: 
     
       1. An apparatus for the distribution of logs into the supply shafts of a plurality of successive grinders from a conveyor line consisting of a plurality of conveyors placed in succession and capable of carrying the logs transversely thereon, the logs being passed from one conveyor to the next and distributed into the supply shafts through logfilled gaps between the conveyors, which conveyors are automatically started for moving the logs on the conveyor line so as to fill shafts which have an insufficient supply of logs, the apparatus comprising: a plurality of sensors for sensing the height of the stack of logs on the conveyor line above each shaft, with two of said plurality of sensors being located at or above the level of each conveyor such that each sensor of said two sensors is adapted to control a respective one of the conveyors adjacent to a given supply shaft, said line being further provided with at least one sensor in each of said supply shafts and adapted to control said adjacent conveyors adjacent each of said supply shafts, so that said adjacent conveyors may be started in motion either simultaneously or separately towards the supply shaft between them to ensure that there is always a sufficient supply of logs at the corresponding grinder.   
     
     
       2. An apparatus according to claim 1, wherein: said conveyors are belt conveyors or chain conveyors.   
     
     
       3. An apparatus according to claim 1, wherein: the stack height sensors are adapted to operate when a shortage of logs appears at a given point on the conveyor line to cause the conveyors located in advance of the log-deficient area to be successively started in motion in a forward direction toward said log-deficient area and stopped, in turn, so that the conveyor line is filled with logs to the edges of its side walls.   
     
     
       4. An apparatus according to claim 3, wherein: the conveyors used in the filling operation, beginning with the second conveyor used, are adapted to run backwards away from an area that has a surplus of logs, in turn, so that the stack surface thereat is substantially even out.   
     
     
       5. An apparatus according to claim 4, wherein: said conveyors are each run backwards for approximately 5 seconds.   
     
     
       6. An apparatus according to claim 1, wherein: two stack height sensors are provided for each supply shaft and are arranged in succession in the direction of movement of the conveyors is such a manner that, as seen from the main direction of log supply, the first sensor above each shaft is located higher than the second sensor.   
     
     
       7. An apparatus according to claim 1, wherein: said one sensor is disposed below the conveyor level and operates after the elapse of a predetermined delay and also when the logs have remained immobile for a time exceeding a set limit to actuate said adjacent conveyors to run alternately in the forward and backward directions.